In the food processing industry large upright band saws such as band saw 10 of FIG. 1 are commonly used for cutting meat products of a variety of sizes. Such band saws typically include a frame 12 upon which is mounted a support surface 14 for positioning meat products to be cut. A housing portion 16 extends above support surface 14 and a housing portion 18 extends below support surface 14. A band saw blade 20 passes though a plane defined by support surface 14 and extends around wheel members (not shown) located with housing portions 16 and 18 for being drivingly rotated by such wheel members. In particular, a drive motor 22 may be connected for rotating a drive wheel in housing portion 18. A blade guard 24 extends around the cutting edge of blade 20 and downward from housing portion 16 toward support surface 14. Blade guard 24 is connected to a guide bar 26 which extends upward toward housing portion 16 and through a guide assembly 28 which is mounted to housing portion 16. Guide bar 26 is slidably positioned within guide assembly 28 such that guide bar 26 can be moved upward or downward through such guide assembly if a sufficient moving force is applied thereto. However, with no moving force applied guide assembly 28 engages guide bar 26 with sufficient force to hold guide bar 26 and blade guard 24 in position. Because blade guard 24 is connected to guide bar 26 for movement therewith, the length of band saw blade 20 which is exposed above support surface 14 can be varied by varying the position of guide bar 26 relative to guide assembly 28. In this manner a variety of different sizes of meat products can be cut with band saw apparatus 10 without requiring exposure of a large length of blade 20 when cutting small meat products.
Referring to FIG. 2, an exploded perspective view of a prior art guide assembly 28 is shown relative to guide bar 26 and blade guard 24. Such guide assembly 28 includes a support member 30, a retaining plate 32, a brake shoe 34, a spring 36, a screw carrier 38, a screw 40 and an end cap 42. Support member 30 may be mounted to housing portion 16 by a bracket assembly 44 (shown in shadow) for example. Support member 30 includes channels 46, 48 through which guide bar 26 passes, with an open face 50 of support member 30 exposing a surface of guide bar 26. When assembled, retaining plate 32 is mounted to support member 30 by a plurality of screws (not shown), plate 32 including an opening 52 therethrough which extends to open face 50 of support member 30. Brake shoe 34, spring 36, screw carrier 38 and screw 40 are positioned withing opening 52 such that spring 36 urges brake shoe 34 into frictional contact with guide bar 26 to support guide bar 26 until the frictional force is overcome. As shown, blade guard 24 may be mounted to the bottom of guide bar 26 by a threaded handle 54.
Although effective, prior art guide assembly 28 is somewhat costly due to the machining requirements of support member 32. Further, guide assembly 28 can be difficult to clean when food material gets caught between retaining plate 32 and support member 30, adding to the time and expense of maintenance and cleaning of the band saw apparatus. Accordingly, it is desirable and advantageous to provide a guide assembly which is relatively simple, inexpensive, and less likely to undesirably trap food product.
In one aspect of the present invention, a guide assembly for receiving a guide bar of a band saw is provided, wherein the guide bar is connected to a blade guard such that a position of the blade guard along a length of a band saw blade varies as a position of the guide bar relative to the guide assembly varies. The guide assembly includes a sleeve-shaped member having first and second ends. A first insert member is positioned within the first end of the sleeve-shaped member such that an outer peripheral surface portion of the first insert member forms a first guide bar receiving channel with an inner peripheral surface portion of the first end of said sleeve-shaped member. A second insert member is positioned within the second end of the sleeve-shaped member such that an outer peripheral surface portion of the second insert member forms a second guide bar receiving channel with an inner peripheral surface portion of the second end of the sleeve-shaped member, with the second guide bar receiving channel being substantially aligned with said first guide bar receiving channel.
The guide bar may be slidably positioned through the aligned guide bar receiving channels. The use of a sleeve-shaped member with two insert members eliminates the costly machining associated with the prior art, particularly where the insert members are formed of a plastic material. Further, preferably each of the insert members includes an exposed end having a peripheral lip which overlaps its respective end of the sleeve-shaped member in a region extending from a first side of its respective guide bar receiving channel around the respective end to a second side of its respective guide bar receiving channel. Such peripheral lips facilitate proper positioning of the insert members in the respective ends of the sleeve-shaped member, and advantageously prevent food product from entering between the outer surfaces of the insert members and the inner surfaces of the ends of the sleeve-shaped member.